[ D'Artagnan hates this. Is he supposed to stand here and argue for the opposite of what he believes? To talk an honourable man into doing what he knows to be wrong, is that what's expected of him?

He can't. He can't do this, he doesn't even want to think about this now. They have Alina, and the other prisoners, and if they're not defeated those people will die. D'Artagnan can't allow that. That's what he needs to be focusing on.

Not the thing that would stay his hand. ]

Spare them, and doom your own world.

[ He says it bluntly, flatly, because it's frankly the only reason he's not arguing for the same thing Steve is. ]

This is not a game. We don't have the option of saying that no one dies, because we are in their power, and we comply, or they destroy all that we love.

[ He can't make it any more clear. He saw what happened to Optimus Prime, and he will not let that happen to Earth. He steps up close to Steve now, angrier than he was, and all the more eager to leave as a result. ]

The people taken are my friends. What's happening isn't their fault, and I won't let them die for it. So you help me, or you get out of my way. I don't care who you are.